Dishwasher appliances generally include a tub that defines a wash compartment. Rack assemblies can be mounted within the wash chamber of the tub for receipt of articles for washing. Spray assemblies within the wash chamber can apply or direct wash fluid towards articles disposed within the rack assemblies in order to clean such articles. Multiple spray assemblies can be provided including e.g., a lower spray arm assembly mounted to the tub at a bottom of the wash chamber, a mid-level spray arm assembly mounted to one of the rack assemblies, and/or an upper spray assembly mounted to the tub at a top of the wash chamber. Other configurations may be used as well.
Dishwasher appliances further typically include a fluid circulation system which is in fluid communication with the spray assemblies for circulating fluid to the spray assemblies. The fluid circulation system generally receives fluid from the wash chamber, filters soil from the fluid, and flows the filtered fluid to the spray assemblies. Additionally, unfiltered fluid can be flowed to a drain as required.
Some known fluid circulation systems utilize a large, flat, coarse filter and a cylindrical fine filter to filter soil. These filters are generally horizontally positioned within the fluid circulation system, and fluid typically flows through either the coarse or the fine filter as it is flowed towards a pump of the fluid circulation system for recirculation.
More recently, improved filter arrangements have been utilized. These filters have perforated sidewalls which are generally vertically positioned and, for example, cylindrical. A pump is at least partially disposed within such a filter. Generally all wash fluid flowed to the pump is flowed through the filter. Such filter arrangements generally provide improved filtering and fluid flow relative to previously known filter arrangements.
However, some issues remain with such improved filter arrangements. For example, a fundamental issue with filters is that they must remain sufficiently clear to allow fluid to flow therethrough. Excess soil that remains on the filter can block such fluid flow. Accordingly, cleaning of the filter to prevent such blockages during operation is desired. One solution is to actively spray fluid at the filter to remove the soil therefrom. However, known arrangements which provide such active spraying constantly divert fluid from the spray assemblies and require that significantly more water is utilized during operation of the dishwasher appliance. The resulting increase in energy and water usage decreases the efficiency of the dishwasher appliance and is thus undesirable.
Accordingly, improved fluid circulation systems for dishwasher appliances are desired. In particular, fluid circulation systems which provide improved fluid filtering, and in particular improved filter cleaning during dishwasher appliance operation, would be advantageous.